The Montreal Protocol for the protection of the ozone layer, mandate the phase out of the use of chlorofluorocarbons (CFCs). Materials more “friendly” to the ozone layer, such as hydrofluorocarbons (HFCs) eg HFC-134a replaced chlorofluorocarbons. The latter compounds have proven to be green house gases, causing global warming and were regulated by the Kyoto Protocol on Climate Change. The emerging replacement materials, hydrofluoropropene, were shown to be environmentally acceptable ie has zero ozone depletion potential (ODP) and acceptable low GWP.
Currently proposed replacement refrigerants for hydrofluorocarbons such as HFC-134a include HFC-152a, pure hydrocarbons such as butane or propane, or “natural” refrigerants such as CO2. Many of these suggested replacements are, flammable, and/or have low energy efficiency. Therefore, new alternative refrigerants are being sought. Fluoroolefin materials such as hydrofluoropropene have generated interest as replacements for HFCs. The inherent chemical instability of these materials in the lower atmosphere provides the low global warning potential and zero or near zero ozone depletion properties desired. However, such inherent instability is believed to also impact their toxicity. In particular, the Z isomer will be much more active towards oxygen compared to the E isomer.
The object of the present invention is to provide novel compositions that can serve as refrigerant and heat transfer fluids as well as blowing agents, solvent cleaners etc. that provide unique characteristics to meet the demands of low or zero ozone depletion potential, lower global warming potential and low toxicity.